Vehicle propulsion system

ABSTRACT

To propel a vehicle along a way, a source of highly compressed gas is provided, for example a turbine generator, which is introduced into a gas tight housing, such as a cylinder, extending along the way of the vehicle. The gas is introduced into the cylinder ahead of a reaction piston secured to the vehicle, with slides in the gas tight housing. The gas tight housing is closed off by means of a flexible rubber strip which is deflected by a holding bar interconnecting the vehicle and the piston as the vehicle travels along the way, and the gas tight housing. Preferably, from time to time, closing shields are placed within the gas tight housing, opening just before the vehicle arrives and closing thereafter.

United States Patent 1 Carrasse [451 July 31,1973

1 VEHICLE PROPULSION SYSTEM [75] Inventor: Jean Carrasse, Antony, France[22] Filed: Nov. 18, 19.70

[21] Appl. No.: 90,643

[52] US. Cl. 104/156, 104/161 680,843 8/1901 Comstock 104/ 156 3,233,5562/1966 McDonald 104/161 3,586,141 6/1971 Henne8sey.... 104/23 FS3,587,471 6/1971 Schneider 104/23 FS Primary ExaminerDrayton E. HoffmanAttorneyFlynn & Frishauf [57] ABSTRACT To propel a vehicle along a way,a source of highly compressed gas is provided, for example a turbinegenerator, which is introduced into a gas tight housing, such as acylinder, extending along the way of the vehicle. The gas is introducedinto the cylinder ahead of a reaction piston secured to the vehicle,with slides in the gas tight housing. The gas tight housing is closedoff by means of a flexible rubber strip which is deflected by a holdingbar interconnecting the vehicle and the piston as the vehicle travelsalong the way, and the gas tight housing. Preferably, from time to time,closing shields are placed within the gas tight housing, opening justbefore the vehicle arrives and closing thereafter.

10 Claims, 9 Drawing Figures [51] Int. Cl 1361b 13/10 [58] Field ofSearch 104/155, 156, 161, 104/23 FS [56] References Cited UNlTED STATESPATENTS 393,701 11/1888 Goebel 104/161 403,729 5/1889 Bodefeld.. 104/1613,155,050 11/1964 Hafner 104/23 FS 376,984 1/1888 Goebel 104/161 409,7698/1889 Bodefeld... 104/161 489,348 1/1893 Vernon 104/156 PATENIED JUL 31 I975 SHEH'I nr 4 PATENTED JUL3 1 I915 sum u or 4 1 VEHICLE PROPULSIONSYSTEM The present invention relates to avehicle propulsion system andmore particularly to a vehicle propulsion system using gas turbines andproviding hot exhaust truck body, or othermovable body destined toprovide transportation for goods and freight of any kind or for people.

Gas turbines have had a rapid development in the last few years,principally for electric energy production,

for peaking units, and in the transport field. One of the difficultiesinhibiting wider application of gas turbines ism however, the large fuelrequirement. Various methods have been proposed to recuperate heat fromgas turbines (see for example, French Pat. No. 1,566,631 assigned to theassignee of the present invention).

Propulsion systems using gas turbines have substantial advantages overdiesel engines, particularly with respect to the power-weight ratio, andcontrol of change of speed. Yet, just as in the case with dieselengines, the transmission of power from the engine to drive wheels posesproblems which result in costly and heavy expenditure of mateials,gears, and the like. The advantages of the light weight of turbo enginesare thus to a certain extent lost, particularly if high speeds are aprime object of the design.

It is an object of the present invention to provide a vehicle propulsionsystem in which mechanical energy derivedfrom gas at highpressure, andproduced on board the vehicle by a generator is directly provided inorder to avoid speed changing arrangements transmitting power from a gasturbine to the wheels of the vehicle.

SUBJECT MATTER OF THE PRESENT INVENTION Briefly, a gas tight conduit ortube is provided along the right of way, or track over which the vehicleis to operate. A piston is located in the tight conduit and mechanicallyconnected to the vehicle, the connecting member passing through a slotin the gas tight tubing which is normally closed off by a flexible flap,leaving an opening just big enough for the connecting member to passtherethrough, the opening travelling along the housing as the flapprogressively deflects. Gas at high pressure is introduced at the sideof the piston opposite the direction of desired motion.

In accordance with the preferred form, the gas generator is a turbogenerator having an air compressor, a combustion chamber, and a gasexpansion turbine to provide power for the compressor; and a heatexchanger to re-heat the compressed air before being ad-. rnitted intothe combustion chamber, in order to recuperate as much heat as possiblefrom the exhaust gases of the turbine. The heat exchanger is preferablyof the type disclosed in Belgian Pat. No. 752,276 (corresponding tocopending application Ser. No. 52,650, filed July 6, 1970, nowabandoned).

The invention will be described by way of example with reference to theaccompanying drawings, wherein:

FIG. 1 is a schematic presentation of a propulsion system;

FIG. 2 is a longitudinal vertical view of the gas tight conduit alongthe track;

FIGS. 3-6 are transverse cross-sectional views along section lines A-A,B-B, C-C, D-D, respectively of FIG. 2 and illustrating, progressively,the placement of the piston within the conduit and the means torendering it gas tight;

FIG. 7 is a transverse view of a vehicle propulsion and suspensionsystem;

a FIG. 8 is a transverse cross-sectional view schematically illustratingan arrangement to close off the gas tight conduit; and

FIG. 9 is a schematic transverse cross-sectional view of a conduitcombined with a track layout to guide the vehicle.

Referring to FIG. 1: A gas turbo generator, generating gas at highpressure is placed on board a vehicle I. This gas generator includes acompressor 2 which supplies, after preheating in a heat exchanger 3, acombustion chamber 4 having fuel applied thereto over a line 4A, supplya turbine 5, mechanically interconnected with compressor 2 and sodimensioned and designed that it supplies only the necessary power forair compression. The high pressure gas escaping from turbine 5 is guidedthrough the heat exchanger 3 in which a great portion of the heat stillcontained therein is given off, without however, substantial loss ofpressure, to be used directly for the propulsion of the vehicle inaccordance with the invention.

The heat exchange system 3 is preferably of the type disclosed in FrenchPat. No. 1,566,631 (above referred to) or as disclosed in the BelgianPatent. Such a heat exchange device includes ducting interiorly of ahousing in which the hot gases under high pressure, from turbine 5, andthe air from compressor 2 are alternatively injected in order to fromsuccessive slices, or blocs of gas, giving off, or receiving heat fromthe internal walls through which the gases pass. The internal ducts thuseffect a thermal heat exchange by acting as an energy storage device,receiving heat from the gas coming from turbine 5 and giving it off tothe air from compressor 2. v

The vehicle 1 is connected with a piston, schematically illustrated at6, and best seen in FIG. 2. The piston can be displaced longitudinallyin a gas tight tube 7, located on, or forming the way along which thevehicle should be moved. Gas at high pressure from vehicle 1 is injectedinto the interior of the gas tight tube 7 at the side of the piston 6opposite the direction of movement to create a pressure which isincreased with respect to that at the other side of the piston 6. Aportion of the air for the compessor can be taken off from the air tighttube 7 at the side of the piston opposite the injection side in order toform a partial vacuum and further assist in movement of the vehicle. Theopposite sides of the piston are thus subjected to differentialpressures and todifierent forces. The piston is caused to move in thesense of the arrow 13 (FIG. 1) under action of a force which is equaltothe diflerence of the forces acting on its opposed faces. Upondisplacement of the piston, the vehicle 1 is carried along thereby bymeans of an arm member 10 (FIG. 3) and not shown in FIG. 1.

Reversal of direction-of movement of the vehicle is easily accomplished.It is only necessary to provide a switch-over valve and remove air fromthe sideof the piston to which it was previously supplied, and supplythe compressed air to the other side. Valves 8, 9 (FIG. 1) can effectthis switch-over. These valves can likewise be used to provide forbraking of the vehicle.

FIG. 2 is a top view of the tight conduit 7 at the moment that a pistonpasses in the interior thereof. A portion of the piston is shown inbroken lines. The arm member (FIGS. 2, 3) interconnects the vehicle andthe piston 6. To provide for a gas tight closing of the tube or conduit7, and still for passage of the piston 6, a longitudinal slit 11 isprovided, closed off by a flap 12, for example of reinforced rubber,plastics or the like which can deflect under action of the arm member 10when a vehicle passes. This action is best seen in connection with FIGS.3 to 6.

The ends of the piston 6 are flared outwardly, as seen at 14 (FIG. 2) toprovide for a close fit of the piston within the conduit 7. This flaredend may be a truncated cone. The cone itself assists in closing of theflap against the wall of the conduit, so that the face of the piston 6beyond the cone 14 will inject (or remove air) from the conduit when intightly closed condition.

FIG. 3 illustrates the position of flap 12 at the moment of passage ofarm 10. Flap 12 is retained on the conduit by means of a clamp 15, orthe like, secured to the conduit in a suitable manner, for example bybolts or welding. The locking clamp is so arranged that the flap 12 candeflect to the interior of the conduit 7 to form an opening 11permitting passage of arm 10 (FIG. 3). To provide for sufficient spacefor the flap 12, the piston can be deformed from a circle to a halfmoon,or crescent shaped form, as best seen in FIG. 3. In the position of FIG.4, the flap has already begun to close. The arm 10 no longer retains theflap in vertical position but it has started to return against theconduit; the crescent at this point can be less pronounced. FIG. 5, asection along lines C-C of FIG. 2 illustrates the position of the flap,almost closed, the piston being now of round shape. In FIG. 5, atransverse section along lines DD, the piston 6 is flared out, and flap12 is completely closed. The end 14 of the piston can be so arrangedthat it resiliently makes contact with the interior of the walls ofconduit 7.

The closing flap 12 preferably has a differential resiliency withrespect to its major dimensions. In the longitudinal direction, it ispreferably highly resilient, and much more so than in the transversedirection. Rubber which is reinforced with fabric in which thetransverse threads or filaments are stiffer than the longitudinal chainfilaments is suitable; or, transverse metallic reinforcement may beused. The action of the pressure of the gas itself, from the faces ofthe piston causes a sealing of the flap surface 1 against the interiorof the wall of conduit 7, to provide a tight seal against the edges ofthe opening 11, without deformation. The flexion under the action of arm10 will be in the form of a smoothly undulating wave.

Tightness is assured by properly dimensioning the respective distances 1forming the overlap of the flap 12 with the interior of conduit 7 andthe length L which corresponds to the width of the slot 11, covering theopening in conduit 7. For an internal pressure of 2 to 3 bars, and a gap11 having a width of from about 2-3 cm, an overlap of about 4 cm issuitable. (See FIG. 6 re-6 the width of the gap 11 is shown distorted)The size of the overlap can be substantially reduced by providing on theinterior of the wall of conduit 7, adjacent the overlap, and at thematching face of the flap, matching grooves and ridges, or the like toprevent slipping of the flap with respect to the interior surface.

Conduit 7 can be used not only for propulsion, but also for suspensionof the vehicle. Referring to FIG. 7, a vehicle having a roof 17 has arm10 secured thereto by means of a bracket 16 secured to the roof by bolts18. The arm 16 will carry the gas conduits. The vehicle will besuspended from above by the conduit 7. FIG. 7 illustrates the positionin which the flap 12 is closed, that is intermediate sections C-C andD--D of FIG. 2. A portion of the gas from the turbine, rather than beingejected beyond the face of the piston to effect propulsion, is injectedbelow the lower zone 19 of the piston by orifices 20 formed in piston 6and between a pair of longitudinal vanes 21. The pressure existing inthis portion of the conduit due to the escaping gas provides a liftingforce to hold the piston in place, and to support the vehicle.

To provide for long distance travel, for acceleration, and braking byforming pressure zones behind, or in ad vance of the piston, as.desired,and to decrease the amount of high pressure gas used, it is desirable todivide the gas tight conduit 7 into successive chambers. These divisionscan be obtained by screens, shutters, flat valves or the like, toprovide for pressure within the conduit from the turbine at all timesregardless of the direction of motion of the vehicle. These screens orshutters must, of course, be removed from the way upon passage of thepiston. FIG. 8 illustrates a closing flap 22, which is pivotally mountedabout an axis 24 in a chamber 23 surrounding the conduit 7. The diskshaped element 22 forms a screen which is removed by a control elementmechanically or electrically operated when imminent arrival of thepiston of a vehicle is sensed by means, well known in the railway field,by and in itself. Such sensing elements which may be electromagnetic orinductive are well known.

Rather than providing rigid screens, elastic membranes secured to aportion of the conduit may be used, which deflect upon passage of apiston towards the internal wall of the conduit, and then resume theclosing position across the conduit after the piston has passed, forexample under the gas pressure obtained therefrom.

FIG. 9 illustrates an arrangement in which the conduit 7 is placedbetween a track arrangement, supporting the vehicle. It is to be notedthat the vehicle wheels are not driven, propulsive power, in accordancewith the invention, being derived only from gas pressure acting on thepiston faces. The conduit 7 is secured to a metal frame 25, for exampleby welding, placed on the ground, for example on crossties or the likeby means of bolts 26. Cross members 27 connect with tracks 28, forexample of C cross section; the internal faces 28 provide guide surfacesfor guide wheels of the vehicle, which may have its wheels run wheredesired.

The propulsion system of the present invention can be used with existingrailway or roadway structures, and does not require complicatedinstallations. The conduit itself is simple and can be light, and thesystem has thus particular applicability for, for example, hybrid typesof transport, in which both road and tracked movement is desired.

The high pressure source for the gas may be other than a turbo generatorand may consist, for example, of a compressor driven by an electricmotor, supplied by any desired power supply.

I claim:

11. Vehicle propulsion system to propel a vehicle along a way comprisingmeans to provide a source of highly compressed gas on board the vehicle;

a gas tight conduit extending the length of the way of travel of thevehicle;

a piston fitting into said conduit;

means mechanically interconnecting the piston and the vehicle; meanslocated in the interior of the conduit transversely sectionalizing theconduit into successive chambers, said means being removable out of theway of the piston upon approach of the piston;

and means connected to said source of compressed gas conducting andintroducing gas into the interior of the conduit at the side of thepiston facing rearwardly with respect to the desired vehicle travel orchange of speed thereof.

2. System according to claim ll wherein the source of highly compressedgas comprises a turbine generator including an air compressor, acombustion chamber, a combustion gas expansion turbine connected to saidcompressor;

and a reheat heat exchanger for the compressed gas located and connectedto preheat air before admission to the combustion chamber forrecuperation of the heat of the exhaust gases of the turbine.

3. System according to claim 2 wherein the heat exchanger comprises ductmeans defined by walls forming a heat storage element;

an alternatively operative injection valve means, al-

ternatively injecting hot gas and air, for heat exchange of the hotgases of heat with the walls, and of the thus heated walls with the airin the duct means.

4. System according to claim 1 including means for removing air from theconduit in advance of the piston in the direction of travel of thevehicle, and introducing said so removed air in the high pressure gasgenerator.

5. System according to claim 1 including gas pressure injection meansdirected to inject gas under pressure between the piston and the innerside wall of the conduit in a direction radially of the conduit.

6. System according to claim 5 including means to direct the gasinjected radially towards the inner wall of the conduit to direct saidgases against the lower portion of the conduit to provide a liftingforce to the piston, and hence to the vehicle connected thereto.

7. A system according to claim 1 wherein the mechanical interconnectionmeans of the piston and the vehicle comprises an arm member;

said conduit being of circular cross section and formed with alongitudinal opening;

an elastic flap normally closing said opening, said flap being shaped tomaintain said circular section of the conduit and being deflectable bysaid arm to locally deflect, and reclose against the conduit beforepassage of the face of the piston against which the gas is injected;

said flap comprising a strip of resilient deflectable material securedat one longitudinal edge to the conduit and bearing with the otherlongitudinal edge against a portion adjacent the opening in the conduitfrom the inside, so that gas pressure within the conduit will maintainthe flap closed and the conduit in air tight condition.

8. System according to claim 7 wherein the resiliently deflectable flaphas a flexibility which is greater in the longitudinal direction than inthe transverse direction.

9. System according to claim 1, wherein said sectionalizing meanscomprise disk-shaped elements pivotally mounted about an axis parallelto the axis of said conduit and outside of the inner volume of thelatter and sensing means sensing arrival of said piston controlling saidelements.

10. System according to claim 1, wherein said sectionalizing meanscomprise membranes secured to the wall of the conduit, the membranesbeing elastically deflectable upon passage of said piston towards theinter nal side of said wall of the conduit.

1. Vehicle propulsion system to propel a vehicle along a way comprising means to provide a source of highly compressed gas on board the vehicle; a gas tight conduit extending the length of the way of travel of the vehicle; a piston fitting into said conduit; means mechanically interconnecting the piston and the vehicle; means located in the interior of the conduit transversely sectionalizing the conduit into successive chambers, said means being removable out of the way of the piston upon approach of the piston; and means connected to said source of compRessed gas conducting and introducing gas into the interior of the conduit at the side of the piston facing rearwardly with respect to the desired vehicle travel or change of speed thereof.
 2. System according to claim 1 wherein the source of highly compressed gas comprises a turbine generator including an air compressor, a combustion chamber, a combustion gas expansion turbine connected to said compressor; and a reheat heat exchanger for the compressed gas located and connected to preheat air before admission to the combustion chamber for recuperation of the heat of the exhaust gases of the turbine.
 3. System according to claim 2 wherein the heat exchanger comprises duct means defined by walls forming a heat storage element; an alternatively operative injection valve means, alternatively injecting hot gas and air, for heat exchange of the hot gases of heat with the walls, and of the thus heated walls with the air in the duct means.
 4. System according to claim 1 including means for removing air from the conduit in advance of the piston in the direction of travel of the vehicle, and introducing said so removed air in the high pressure gas generator.
 5. System according to claim 1 including gas pressure injection means directed to inject gas under pressure between the piston and the inner side wall of the conduit in a direction radially of the conduit.
 6. System according to claim 5 including means to direct the gas injected radially towards the inner wall of the conduit to direct said gases against the lower portion of the conduit to provide a lifting force to the piston, and hence to the vehicle connected thereto.
 7. A system according to claim 1 wherein the mechanical interconnection means of the piston and the vehicle comprises an arm member; said conduit being of circular cross section and formed with a longitudinal opening; an elastic flap normally closing said opening, said flap being shaped to maintain said circular section of the conduit and being deflectable by said arm to locally deflect, and reclose against the conduit before passage of the face of the piston against which the gas is injected; said flap comprising a strip of resilient deflectable material secured at one longitudinal edge to the conduit and bearing with the other longitudinal edge against a portion adjacent the opening in the conduit from the inside, so that gas pressure within the conduit will maintain the flap closed and the conduit in air tight condition.
 8. System according to claim 7 wherein the resiliently deflectable flap has a flexibility which is greater in the longitudinal direction than in the transverse direction.
 9. System according to claim 1, wherein said sectionalizing means comprise disk-shaped elements pivotally mounted about an axis parallel to the axis of said conduit and outside of the inner volume of the latter and sensing means sensing arrival of said piston controlling said elements.
 10. System according to claim 1, wherein said sectionalizing means comprise membranes secured to the wall of the conduit, the membranes being elastically deflectable upon passage of said piston towards the internal side of said wall of the conduit. 